Fuel injection valve device



March 10, 1970 R. THQ soN r "Fum- INJECTION VALVE DEvigE;

Filed 'lly" '2, 1968 N am W 0 Y 8 a 2 m M M m /mm m A I. A u M m 0Q m va a. 5 v lli'd g a a 4 United States Patent 3,499,607 FUEL INJECTIONVALVE DEVICE Millard R. Thomson, Sidney, N.Y., assignor to The BendixCorporation, Sidney, N.Y., a corporation of Delaware Filed May 7, 1968,Ser. No. 727,253

' Int. Cl. 1305b 1/32 US. Cl. 239-533 14 Claims ABSTRACT OFITHEDISCLOSURE "ice the illustrative embodiment of the device of theinvention, certain of the parts being shown in elevation;

FIG. 2 is a view similar to FIG. 1 on a greatly enlarged scale of theportion of the device adjacent the nozzle end thereof;

FIG. 3 is a view in end elevation of the main body of the device,-thefigure being taken in the direction from right to left in FIGS. 1 and 2;and

FIG. 4 is a view in end elevation of the forward end of the nozzle body,such view being taken in the direction from left to right in 'FIGS. 1and 2 on line 4-4 of FIG. 2.

In prior fuel injection valve devices, the nozzle body,

/ or an element which in eifect forms an extension of the opened by highpressure fuel delivered to the nozz e; A

high pressure fuel passage extends within the main body of the deviceand into the body of the nozzle to the valve seats therein; a lowpressure leakage fuel return passage extends rearwardly through the mainbody of the device.

The device of the invention includes improved means for effecting a sealbetweenthe'parts of the high pressure fuel passage in the main body ofthe device and the nozzle body. v

This invention relates to a va ved nozzle for the spray% c portionsbeing sealed to each other. I g v The invention, has among its objects.theprovision of animproved fuel injection valve device having the partsthereof so constructed andarranged that the required seal beween theconfronting-ends of the portions ofthe pa'se sages in the main bodyjandthe nozzle body of the. device a es I mO tflicient use of the areas-inthe device available for sealing. j A furthervobject of theinv'entiomresidesrin the proand within the nozzle body, such nozzlebody, is secured to the rear end of a main body or nozzle holder inalignment therewith. A reciprocable valve element or needle is mountedwithin a central longitudinal bore in the nozzle body, the forwardportion of the needle projects forwardly from the nozz e body into anaxial bore in the main body of the device, the forward end surface ofthe needle engaging an axially disposed pressure rod or spindle which isurged rearwardly by a coil compression spring;

High pressure fuel is fed through a longitudinally dis posed passage inthe main body of the device, such passage extending to the rear end ofthe main body. In the annular forward transverse end surface of thenozzle body and coaxial thereof there is provided an arcuate groovewhich communicates with the rear end of the passage in the main body,two generally longitudinally extending passages in the extension of thenozzle body extending from said arcuate groove to diametrically opposedsides of an annular enlarged zone of the central bore in the nozzlebody. Fuel is fed from such zone of the bore to the spray orifices ofthe device when the valve thereof is opened. 4

The required seal between the rear end of the main body and the forwardend of the nozzle body or the extension thereof is formed by a surfaceto surface engagement of such bodies. It willbe seen that thereare thusrequired two complete zones of high pressure sealing between the twobodies, one on each side of the forward end of thegenerallylongitudinally extending passages in the nozzle body. As willbe seen below, the present invention reducesthe length of the boundarysurrOundingthe vision of the required seal in the above device in-amini-- mum of 'space, whereby :the: sealing-surface area isincreasedascompared to thatjof prior devices of the. same diameter, or, ;whenthediameter of the device} is reduced, the sealing surfaceareamay bemadethe; same as that of larger diametered prior devices.

It'is also an object Of,'tl1e, pre'sent invention to provide, in adevicehaving? high pressure seal infacco'rdance with the invention, conduit"means, incorporating a-further sealing means related to the first:recited sealing to obtain the desired security of sealing between theparts.

means, for the exhaust of'leakage fuel from the device.

The above and further objects andinov'elfeatures of the invention willmore fully appear from the-following description when-the samegjis readin connection. with. the accompanying drawings.'lt is to be expresslyunderstood,

however, that the drawings are for the purposeofillus- FIG. 1 is a viewin longitudinal axial section through high pressure conduitmeans at'theseal, and localizes the high, pressure conduitjm'eans to one-side of thedevice at the seal, thereby to eliminate one sealarea which was formerlynecessary and to make itpossiblemore readily Atthe same time, the devicealso readily providesfor the secure, sealing of the path ofdischarge'oflow pressure leakage fuel from the device.

Turning now to the drawings, the illustrative fuel ini jection valvedevice shown in FIGS. 1- and 2 includes an elongated main r nozzleholder body 1(I and a spray nozzle body llhaving'a smaller diameter rearend 18 and alargerdiametered forward end 42.j'Parts 10'and 11 are heldin coaxial-aligned relationship by an assembly sleeve or nut 12 havingshoulder "to shoulder engagement at 13 with the' body 11 andthreadedengagement at 37 with the smaller diame'tered rear end portion 23'0'f,the'body'-10-. The rear end of the device, shown-at the fight inFIGS. 1 and 2,: is adapted to extend throughan opening in the wall ofacylinderiof an-internal'combustion engine, being retained therein byconventional'means not shown; The device'is sealed to the wall of thecombustion chamber of theengine by a gasket 14 disposed aboutthe-nozzle-body 1.1 and engaging therear end offth'enutlz; I v;

Liquid fuel under high pressure is fed into a port 15 in the forward endof the body through a conduit (not shown) attached to such main body.Such fuel travels through conduit means, to be described, in bodies 10and 11, being discharged through a plurality of orifices 16 in the noseportion 17 at the rear end of the nozzle body. Leakage fuel, that is,fuel in the device which leaks past the needle flows into the rear endof the eccentric bore 32 in the main body 10 of the device and thencethrough a discharge passage 62 is discharged to a suitable tank or sumpthrough a branch conduit 19 which is held upon the body 10 by an annularfitting 20 as shown in FIG. 1.

The novel structure of the device is more particularly shown in FIGS. 2,3, and 4. As shown in FIG. 2, the nozzle body 11 has an axial bore 21therein, there being an enlarged annular zone 22 in the boreintermediate the length thereof. Bore 21 extends from the forwardtransverse end surface 24 of the body 11 to a rearwardly convergingfrusto-conical valve seat 25, rearwardly of which there extends a smallaxial bore or sac hole in nose portion 17 in communication with theorifices 16. A reciprocable elongated noule needle or valve element 26is disposed within the bore 21; the rearward portion 29 of the needlehas a diameter somewhat less than that of bore 21, whereas the forwardend portion 30' of the needle is of larger diameter and fits fairlyaccurately within the bore 21. The two portions 29 and 30 of the needleare joined by a shoulder 28 which lies forwardly of the enlarged zone 22of the bore. As its rear end the needle has a conical end 27 forming asecond valve seat cooperating with the seat 25. The forward end portion30 of needle 26 functions as a piston to retract the needle to itsvalve-open position when the space within the enlargement 22 of the bore21 is subjected to high pressure fuel. The rear end surface 31 ofportion 30 of the needle is constantly urged toward the valve closedposition by a needle stop means 50, to be described, disposed within therear end of the main body 10.

Within the rear end of the main body 10 there is disposed a second,rearwardly open and forwardly blind bore 32 which is parallel to thebore 21 in the nozzle body but has its axis offset from the axis of bore21 through a distance E. There is thereby formed a sidewall in the rearend of the body 10 around the bore 32 which is of varying thickness, thesidewall and the rear end surface 35 of portion 23 of 'body 10 beingthickest at a zone 34 and thinnest at a zone 36, as shown in FIG. 3. Asingle high pressure fuel supply passage 39 extends angularly from thecentral port at the outer end of the main body 10 generallylongitudinally of the body 10 to terminate within such body at alocation 40 which is disposed radially outwardly of and somewhatforwardly of the eccentric bore 32. Two small bores 41 extend from theend 40 of the passage 39 longitudinally of the smaller diametered, rearend portion 23 of body 10, the passages 41 lying parallel, spaced midwayof the radial thickness of zone 34 of the portion 23 of body 10 and atequal distances from a radial axial plane therethrough, as shown in FIG.3. p v I The forward larger portion 42 of the nozzle body 11 has adiameterequal to the diameter of the rear end portion 23 of body v10.When bodies 10 and 11 are assembled in operative position, as shown inFIG. 2, the transverse end surface 24 of body 11 engages the tranverseend surface 35 of the body 10. Disposed in the transverse end surface 24of the body 11 is an arcuate groove 44 of such size as to enclose andcommunicate with the rear ends of the passages 41 in body 10. Extendingangularly rearwardly from the ends of groove 44 are two parallelpassages 45 in portion 42 of body 11, the passages 45 extending. to

drawn together by the nut 12, outer and inner seals 46 and 47 are formedbetween such end surfaces, such seals surrounding the rear ends of thepassages 41 in body 10 and the arcuate groove 44 in body 11. Because ofthe above described eccentric location of the bore 32 with respect tothe bore 21, such sealing zones 46 and 47 may be made with widths whichare at least equal to those in the described prior art devices eventhough the device of the invention is made with a diameter which issubstantially less than that of such prior devices. The sealing surfacesof zones 46 and 47 are readily formed and finished by lapping toWithstand without leaking the relatively high pressure of the fuelsupplied to the device.

Not only are high pressure seals 46 and 47 formed between the bodies 10and 11 as above described, but a further, low pressure seal is formedcompletely about the confronting end surfaces of such bodies whichdefine the communicating ends of the bores 21 and 32. The portion ofsuch low pressure seal at the radially thinner zone 36 of the sidewallof the bore 32 is designated 49 in FIG. 2. As will be apparenthereinafter, leakage fluid which seeps between the forward portion 30 ofthe nozzle needle and the wall of bore 21 flows into the bore 32 andthen outwardly therefrom through a passage 62 which communicates withthe above mentioned discharge pipe 19.

Disposed within the bore 32 is a needle stop means generally designated50. Such stop means has an elongated stem 51, disposed axially of thebore 32, and a disc-like head 52 secured to the rear end of the stemcoaxially thereof. The peripheral, circular cylindrical surface of head52 is finely finished, and is of such diameter as accurately to fit thebore 32 so as to serve as a pilot or guide for the needle stop. The head52, which is disposed eccentric of the needle 26, is constantly thrustrearwardly into engagement with the forward end surface 31 of the needleby a coil compression spring 53 which is telescoped about the stem 51 ofthe stop means coaxially thereof and acts between a stop plate or disc54 in the forward, blind end of the bore 32 and the forward end of astack 56 of washer-like shims which are telescoped over the stem 51 andabut the head 52 of the stop means. As shown, the spring is of an outerdiameter which is close to but slightly less than the diameter of bore32. When the nozzle needle is in its rear, closed position, the forwardend 55 of the stem 51 is spaced from the stop plate 54 by apredetermined distance or lift L, as shown in FIG. 2. The stop plate 54has a diameter which is somewhat less than the diameter of bore 32. Theforward, blind end of the bore 32 is provided with an annular groove 61into which leakage fuel seeps past the edges of the stop plate 54. Therear end of the above described leakage fuel discharge passage 62communicates with the groove 61, as shown in FIG. 2.

As shown in the drawings, and as above described, the needle stop 50 andthe spring 53 are disposed with their longitudinal axes parallel to buteccentric of the longitudinal axis of the needle 26. It was heretoforeconsidered that it was not possible to have the needle stop and itsspring disposed eccentric to the needle, because it was thought thatboth the needle and the spring would rock or cock the needle stop out ofalignment with the axis of the bore 32. It has been found, however, thatthe device shown and described performs entirely satisfactorily whenconstructed as follows. The projection of the longitudinal axis of theneedle stop 50, that is, of the stem 51, head 52, and spring 53, shouldlie within the cross sectional area of the forward end of needle 26. Theprojection of the forward end of needle 26 should lie within theprojected area of the head 52 of the needle stop, that is, the rearsurface of head 52 should engage the entire end surface of needle 26.When the device of the and piercing the wall of the bore 21 at oppositesides of the annular enlargement 22- therein. The transverse endsurfaces 35 and 24 of the bodies 10 and 11,- respectively, areaccurately finished so that when the bodies are forcibly invention isconstructed within the above design limits the needle stop reciprocatesfreely in bore 32 and does not tend to rock out of the axis of bore 32nor does the head 52 tend to bind in such bore.

In order to insure the assembly of the bodies and 11 in the properangular relationship, index marks 59 and 60, respectively, are providedupon them as shown in FIG. 2. Such index marks areso positioned thatwhen they are aligned" the rear ends of passages 41' are accuratelyaligned with the arcuate groove 44 in body 11, thereby insuring thecorrect registration of the'portions 41, 44, and 45 of the fuelsupplying passage in the bodies 10 and 11. The index mark 60'is alsodesirably fixedly related to the various spray orifices 16, which in theembodiment shown are equally angularly spaced about the axis of the body11. Other index marks may be' substituted for marks 59 and 60, ifdesired. Thus opposed parallel fiat surfaces accurately angularlyoriented about the body may be provided on the outer surface of body 10in place of index mark 59, as for example at the forward end of suchbody.

Although only one embodiment of the invention has been illustrated inthe accompanying drawings and described in the foregoing specification,it is to be especially understood that various changes, such as in therelative dimensions of the parts, materials used, and the like, as wellas the suggested manner of use of the apparatus of the invention, may bemade therein without departing from the spirit and scope of theinvention, as will now be apparent to those skilled in the art.

I claim:

1. In a fuel injection valve device having an elongated main body, anozzle body, means to secure the two bodies together in alignedrelationship, a first, longitudinally directed central bore having afirst valve seat in the nozzle body, a reciprocable valve element withinthe bore in the nozzle body, said valve element having a second valveseat cooperating with the first valve seat, resilient means forconstantly urging the valve element rearwardly toward its closedposition, and means for retracting the valve element to open the valveby high pressure fuel delivered to the bore in the nozzle body, theimprovement which comprises a rearwardly open, second bore in the rearend of the main body, said second bore being disposed parallel to,markedly-eccentric to, and overlapping the first bore, the sidewall ofthe main body radially outwardly of the second bore being markedlythicker at a first zone than at a second, diametrically opposite zone, aplunger in the second bore, resilient means for constantly urging theplunger rearwardly into engagement with the valve element to thrust thevalve element rearwardly toward its valve closed position, a first highpres sure fuel conducting passage in the main body, the rear end portionof such first passage extending longitudinally, and generally centrallyin a peripheral direction, through the first, radially thicker zone ofthe sidewall of the main body radially outwardly of the second bore,said first passage extending to the rear end of the main body, and atleast one second passage, disposed in the nozzle body, which extendsfrom the forward end surface of the nozzle body to the bore in thenozzle body, the rear and forward ends of the first and second passages,respectively, communicating and being sealed together to form a conduitfor forwarding fuel from the first passage to the first bore.

2. A device according to claim 1, wherein the main body has a transverserear end surface, the nozzle body has a transverse forward end surface,said two end surfaces being in engagement, the rear and forward ends ofthe first and second passages, respectively, being sealed together byengaging zones of the said transverse end surfaces of the bodies whichsurround the confronting ends of the first and second passages.

3. A device according to claim 2, wherein the rear end portion of themain body containing the second bore is circular cylindrical, and theforward end portion of the nozzle body containing the forward end of thefirst bore is circular cylindrical.

4. A device according to claim 3, wherein the rear 'end portion of themain body and the forward end portion of the nozzle body are of the samediameter and are disposed coaxially.

5. A device according to claim 2, wherein said first passage has afirst, larger diametered forward portion, the rear end of which liesadjacent the forward end of the second, eccentric bore, and a pluralityof generally parallel second, smaller diametered branch portionsextending from the rear end of the first portion alongside the secondbore to the rear end surface of the main body.

6. A device according to claim 5, comprising a plurality of generallyparallel second passages in the nozzle body having their forward endssealed to the rear ends of the second branch portions of the firstpassage.

, 7. A device according to claim 6, wherein the first bore is ofsubstantially less diameter than the second bore and comprising anarcuate groove in the forward end of the nozzle body connecting andsubstantially encompassing the forward ends of the second passages.

8. A device according to claim 1, wherein the second, eccentric bore isblind in a forward direction, the plunger has a stem and an enlargedhead at the rear end of the stem, the head being engaged eccentricallyof its axis by the forward end of the valve element, and the meansresiliently thrusting the plunger rearwardly comprises a coilcompression spring telescoped about the stem of the plunger and held incompression between the forward end of the second bore and the head ofthe plunger.

9. A device according to claim 8, wherein the head of the plunger isdisposed coaxially of the plunger and accurately and guidingly engagesthe wall of the second bore, and the springhas an outer diameter whichis close to but slightly less than the diameter of the second bore.

10. A device according to claim 2, wherein the rear end of the secondbore is sealed to the forward end of the first bore by engaging zones ofthe said transverse end surfaces of the bodies which surround theconfronting ends of the first and second bores, and comprising a third,low pressure leakage fuel exhaust passage leading from the second,eccentric bore.

11. A device according to claim 10, wherein the second, eccentric boreis blind in a forward direction, and comprising a stop plate within andloosely fitting the forward end of the second bore and adapted to beengaged by the forward end of the plunger, and a groove in the forwardwall of the second bore beneath the stop plate, and wherein the fuelexhaust passage extends from said groove generally longitudinally of themain body.

12. A device according to claim 1, wherein the projection of thelongitudinal axis of the plunger lies within the cross sectional area ofthe forward end of the valve element.

13. A device according to claim 1, wherein the projection of the forwardend of the valve element lies within the projected area of the end ofthe plunger which it engages.

14. A fuel injection device having an elongated main body with atransverse rear end surface, a nozzle body having a transverse forwardend surface, means to secure the two bodies together in coaxial alignedrelationship and to thrust them together with their respectivetransverse end surfaces in sealing engagement, a first, longitudinallydirected central bore in the nozzle body, a reciprocable valve elementwithin the bore in the nozzle body, means for moving the valve elementforwardly to open the valve by high pressure fuel delivered to the borein the nozzle body, a rearwardly open, second bore in the rear end ofthe main body, said second bore being disposed parallel to, markedlyeccentric to, and overlapping the first bore, the sidewall of the mainbody radially outwardly of the second bore being markedly thicker at afirst zone than at a second, diametrically opposite zone, means in thesecond bore engaging and constantly urging the valve element rearwardlytoward its valve closed position, a first high pressure fuel receivingpasage in the main body, said first passage extending in the main bodyto emerge at a zone of the transverse rear end surface of the main bodywhich lies generally centrally of the thicker portion of the sidewall ofthe second bore in directions both peripherally and radially thereof,and at least one second passage, disposed in the nozzle body, whichextends from the forward transverse end surface of the nozzle body tothe first bore, the rear and forward ends of the first and secondpassages, respectively, communicating and being sealed together by saidengaging surfaces of the main body and the nozzle body to forward fuelfrom the first passage to the first bore.

. References Cited UNlTED STATES PATENTS M. HENSON WOOD, R, PrimaryExaminer I. I. LOVE, Assistant Examiner

